Fire Coral Cuts and Stings Overview

Fire corals are not true corals. Fire corals (Millepora alcicornis) are members of the Cnidaria phylum, and although fire coral looks like coral, it is a member of the class Hydrozoa and more closely related to jellyfish and other stinging anemones. Fire corals are typically encountered off the Florida coast, in the Caribbean reefs and across the Bermuda platform. In addition, fire corals are sessile (fixed in one place) creatures that can attach to rocks, coral, seaweed, or pilings. The painful stings of M. alcicornis are inflicted using the cnidae (stinging threads), which are released from a cnidoblast on its surface. These are used to stun prey. Fire coral have minimal toxicity. These organisms inflict predominantly local pain, usually described as stinging or burning, and possible rash.

Fire corals have a bright yellow-green and brown skeletal covering and are widely distributed in tropical and subtropical waters. Scuba divers often mistake fire coral for seaweed, and accidental contact is common. The very small cnidoblast (an organ in some marine animals consisting of a minute capsule) on fire corals contain tentacles that protrude from numerous surface pores. In addition, fire corals have a sharp, calcified external skeleton that can scrape the skin.